 It means even though Thursday marks the third debate between these two, this debate is likely to be more important than the first two because a larger share of the electorate is potentially up for grabs. And the early timing of the debate also has the potential to change the trajectory, the narrative of the race for the next few weeks or months, especially if tonight's debate turns out to be the only one. There's supposed to be another one in September, but you never know. If it goes badly enough for one of them, there may not be another debate.